Remote control system



Jan. 15, 1935. E. WHITBY ET AL 1,983,257

REMOTE CONTROL SYSTEM Filed March 3, 1952 INVE NTORS Z W/zz'ZZ'y A Zflfl Padler 75 12 ZJ56Z$ZOJZ Z13. Zesier 33 43 4/ BY W 42 ATTOR EY Patented Jan. 15, 1935 UNITED STATES PATENT OFFICE REMOTE CONTROL SYSTEM England Application March 3,

1932, Serial No. 596,560

In Great BritainMarch 9, 1931 2 Claims.

The present invention relates to remote control systems and more particularly to an electric remote control system for the control of other electric circuits.

Objects and advantages of the invention will be set forth in part hereinafter and in part will be obviousherefrom, or may be learned by practice with the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended claims.

The invention consists in the novel parts, con structions, arrangements, combinations and improvements herein shown and described.

The accompanying drawing, referred to herein and constituting a part hereof, shows illustrative embodiments of the invention, and together with the description, serve to explain the principles of the invention.

0f the drawing:- I

Figure 1 is a diagrammatic circuit diagram showing the present preferred embodiment of the invention; and

Figures 2 and 3 are fragmentary circuit diagrams showing modified arrangements of the receiving device in accordance with the present invention.

The present invention has for its object the provision of a remote control system for carrying out predetermined operations at one or more receiving stations distant from a central transmitting station and using the usual alternating current network for at least one of the parts of the control circuit. Another object is the provision of a remote control system which is simpler and more inexpensive than those now generally employed.

The remote control system of the present invention is particularly adapted for use in controlling the change-over in multiple tariff meters, the actuation of switches for street-lighting, the switching on and off of motors and other apparatus from a central station, and for performing other similar operations.

In accordance with the embodiment of the invention illustrated in Figure 1 of the drawing, the transmitting device is designated generally as A and the receiving device is designated generally as B. The alternating current net-work comprises the high tension conductors '7 which supply current to the primary windings 8 of the transformer and induce a current in the secondary windings 9 from which current is supplied to the low tension lines 10.

The transmitting device A comprises a transformer 11, having its primary winding 12 connected with two conductors of the high tension net-work 7. The secondary winding 13 is connected to supply power to a switchactuated solenoid 14 under control of switch 15, and also to supply power to the primary winding 16 of transformer 17 under control of the switch 18. The secondary winding 19 of transformer 17 is connected to ground 20 at one end and at its other end to the star point of the star-connected bank of impedance coils 21 which are connected with the high-tension conductors 7. Switch 18 is adapted to be closed as solenoid 14 is energized, and simultaneously therewith switch 22 is open, thereby opening the normally closed shunt conductor 23 connected across the secondary Winding 19.

Any suitable means may be provided for closing the switch 15, and closure of this switch causes the primary winding 16 and transformer 17 to be supplied with current from transformer 11 and thereby impresses a current on the high tension conductors 7 and ground 20.

The receiving device B comprises a star-connected bank of impedance coils 24, the star point of which and ground 25 are connected with a switch-actuating solenoid 26. An auto-transformer 27 has its primary winding 28 and secondary winding 29 connected to the star point of secondary winding 9, while the primary winding 28 has one end connected with one low tension conductor 10 through switch 30, while its secondary 29 is normally shunted through switch 31. One side of the secondary winding 29 is also grounded at 32. When solenoid 26 is not energized, switch 30 is open and switch 31 is closed, but when solenoid 26 is energized the position of these switches is reversed, and current is supplied from transformer 27 to the neutral conductor 33 and ground 32.

The receiving relays or control mechanisms 34, 34a and 34b for effecting the various desired operations are connected in parallel between the neutral conductor 33, and their respective grounds 35, 35a and 351), so that they receive energy from the secondary winding 29 whenever solenoid 26 is energized.

The relays or control mechanisms 34 may be of any desired construction to be selectively and independently actuated by the impulses from transformer 27, dependent upon the duration or number of the impulses, and serve to operate multiple tariiT meters, switching mechanism or the like.

Each time that switch is closed, solenoid l4 is energized, supplying current to transformer 17 from transformer 11, and the secondary shunt 23 of transformer 17 is opened so that the output is fed to the star-connected impedance coils 21 and ground 20. This current is carried along the high tension net-work and flows through the star-connected impedance coils 24 to ground 25 energizing solenoid 26 which actuates the switch 30, 31, thereby supplying transformer, 2'7

with current and at the same time interrupting the secondary shunt by means of switch 31. The output of transformer 27 is impressed on the neutral carrier 33 and ground 32 by which it is supplied to the relays 34.

The grounds 20, 25, 32, etc. may be either the earth or cable sheaths, or, if desired, separate conductors, but the neutral conductor 33is= preferably a separate conductor and insulated from the ground, cable sheaths, and other conductors.

Whenever the switch 15 is not closed, the neutralconductor 33 has no potential relatively to the-earth, and the voltage of the individual phase conductors relatively to the earth is then the same as the phase of star voltage. During transmission, however, the voltage of all the network conductors relatively to theearth changes, although the voltages of the phase conductors relatively to each other and to the neutral conductor is not aifected. The voltage of the various conductors of the network with respect to the ground is determined by vectorially adding the transmitting voltage to the voltages existing between transmission impulses, and it will be understood that the phase conductor which carries the control current, has the greatest variation in voltage relatively to the ground during transmission. This variation of voltage is equal to the transmitting voltage and is either an increase or decrease dependent upon the polarity of the transmitting transformer.

, As connected at the receiving apparatus, the neutral conductor is of opposite polarity to the ground and therefore the voltage of the phase supplying the current is reduced with respect to the ground. The control voltage in this case is displaced by 60 relatively to the phase voltages of the other two phases, and the voltages of these two phase conductors relatively to the earth is thus increased, but only by about onehalf the full value of the controlling voltage. This method of connection is advantageous as the insulation of the network from the ground is not subjected to undue strain.

In accordance with the modified embodiment of the invention, as shown in Figure 2 of the drawing, the current impulses received at the receiving transformer are transmitted directly from the high tension side to the low tension side of; the system by means of a bridging transformer. In this modified embodiment the current network having a neutral rent impulses are received by and passed through the primary 40 of a transformer 41, the primary being connected to the star-connected inductance coils 24 and grounds 42, while the secondary winding 43 is connected toground 42, neutral conductor 33 and the star point of secondary winding 9.

When it is desired to employ'the present invention in connection with an alternating curconductor grounded at a plurality of points, it is necessary to employ a separate conductor independent of the network, as shown in Figure 3. In this "figure-,the central conductor 33 is grounded at a plurality of points 45, and a separate conductor i6 must be provided for the current circuit of the controlled relays.

The invention in its broader aspects is not limited to the specific mechanisms shown and described but departures may be made therefrom within the scope of the accompanying claims without departing from the principles of the inventionand without sacrificing its chief advantages. 1

1. In a remote control system, thev combination of a polyphase network, a transformer supplied by one phase and delivering its output to a neutral conductor and an artificial neutral point onrsaid network, a second neutral point and an electrically actuated switch connected thereto and to the neutral conductor, a power transformer in said polyphase network, a control transformer energized by one phase of the power' transformer output and under control of said switch and electrically actuated control devices connected to a neutral point and neutral conductor and actuated by current from said control transformer.

2. A remote control system for actuating electric control mechanism at a receiving station distant from the central transmitting station including in combination an alternating current network, a neutral conductor, and an impulse transmitter including a transformer connected to the network and neutral conductor, and a switch normally shorting said transformer and adapted to energize said transformer, a second transformer located at the receiving station and connected to the network and neutral conductor, a switch actuated by impulses transmitted from said first switch and normally shorting said second transformer, and a plurality of electrically actuated control devices supplied with power by said second transformer.

,ERNEST WHITBY.

IVOR AUGUSTUS DURANT PEDLER. ERNEST JOSEPH vSELSTON.

LLEWELLYN ROLLS LESTER. 

